VoIP network architectures and QoS strategy

Voice over IP (VoIP) has received much attention in recent years with the promise of lower costs, aswell as new revenue‐generating services. Cost and services advantages of carrying voice over IP compared toover the current circuit network are made possible by a common high‐capacity packet infrastructure forvoice, data, and multimedia services. An important requirement of such a packet infrastructure is the ability toprovide public‐switched telephone network (PSTN) grade quality without excessiveover‐provisioning. In this paper, we describe an approach to offer AbsoluteQoS™ to voice and otherdemanding applications over a general‐purpose packet network. AbsoluteQoS is defined as the ability toprovide an engineered bound on call‐blocking and quantitative QoS guarantee thatcalls‐in‐progress will receive. The proposed strategy is based on key innovations in architecturesand protocols, as well as business models of PSTN and packet networks. © 2003 Lucent Technologies Inc.